From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753118AbbJTUh0 (ORCPT ); Tue, 20 Oct 2015 16:37:26 -0400 Received: from mail-am1on0066.outbound.protection.outlook.com ([157.56.112.66]:3384 "EHLO emea01-am1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753153AbbJTUhN (ORCPT ); Tue, 20 Oct 2015 16:37:13 -0400 Authentication-Results: spf=fail (sender IP is 12.216.194.146) smtp.mailfrom=ezchip.com; ezchip.com; dkim=none (message not signed) header.d=none;ezchip.com; dmarc=none action=none header.from=ezchip.com; From: Chris Metcalf To: Gilad Ben Yossef , Steven Rostedt , Ingo Molnar , Peter Zijlstra , Andrew Morton , "Rik van Riel" , Tejun Heo , Frederic Weisbecker , Thomas Gleixner , "Paul E. McKenney" , Christoph Lameter , Viresh Kumar , Catalin Marinas , Will Deacon , Andy Lutomirski , , CC: Chris Metcalf Subject: [PATCH v8 10/14] arch/arm64: adopt prepare_exit_to_usermode() model from x86 Date: Tue, 20 Oct 2015 16:36:08 -0400 Message-ID: <1445373372-6567-11-git-send-email-cmetcalf@ezchip.com> X-Mailer: git-send-email 2.1.2 In-Reply-To: <1445373372-6567-1-git-send-email-cmetcalf@ezchip.com> References: <1445373372-6567-1-git-send-email-cmetcalf@ezchip.com> X-EOPAttributedMessage: 0 X-Microsoft-Exchange-Diagnostics: 1;DB3FFO11FD005;1:e9IAiQJg/28YQ0mC4f48IF2r7c96YLYkrM9PUzejPK695ZZHpwrEyUf0VUwURg6wKMPjoJRjFceavbPTj86ltOmdUWqWq095t0l5Xuaj7dRVUnAhmVDYf8ykU57onJhR4VqgsD7EF1RtEufvcc8/wFfGhdUtdsUlboWQWypnX3EZ0bLAigXrZGGe3lmlaVTpkilYWLX2wgzmMHclNlU1JIED5cDWhNxHLN/3WkBB7ajVP9jL6JY9hhGkT7ELk0an6vTzZAh8fnEMFNQxgwuO8/V39wuGJfENQJIPdZQ5CjvuYJiWIftyJKJs6z/zK58a2Tsk84VMrS9jSab//+3gJ3gzbj8SwlZX/ZyLbYr/5ng= X-Forefront-Antispam-Report: CIP:12.216.194.146;CTRY:US;IPV:NLI;EFV:NLI;SFV:NSPM;SFS:(10009020)(6009001)(2980300002)(1109001)(1110001)(339900001)(199003)(189002)(189998001)(5008740100001)(107886002)(86362001)(50226001)(48376002)(64706001)(46102003)(47776003)(33646002)(76176999)(5007970100001)(50466002)(6806005)(81156007)(36756003)(5001770100001)(2950100001)(97736004)(5003940100001)(19580405001)(105606002)(106466001)(106476002)(87936001)(92566002)(106356001)(42186005)(85426001)(2201001)(104016004)(11100500001)(5001960100002)(19580395003)(50986999)(229853001)(9376005)(921003)(1121003)(4001430100001)(2101003)(83996005);DIR:OUT;SFP:1101;SCL:1;SRVR:DB4PR02MB0429;H:ld-1.internal.tilera.com;FPR:;SPF:Fail;PTR:InfoNoRecords;A:1;MX:1;LANG:en; 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The existing arm64 do_notify_resume() is called in a loop from assembly on the slow path; this change moves the loop into C code as well. For the x86 version see commit c5c46f59e4e7 ("x86/entry: Add new, comprehensible entry and exit handlers written in C"). Signed-off-by: Chris Metcalf --- arch/arm64/kernel/entry.S | 6 +++--- arch/arm64/kernel/signal.c | 32 ++++++++++++++++++++++---------- 2 files changed, 25 insertions(+), 13 deletions(-) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 4306c937b1ff..6fcbf8ea307b 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -628,9 +628,8 @@ work_pending: mov x0, sp // 'regs' tst x2, #PSR_MODE_MASK // user mode regs? b.ne no_work_pending // returning to kernel - enable_irq // enable interrupts for do_notify_resume() - bl do_notify_resume - b ret_to_user + bl prepare_exit_to_usermode + b no_user_work_pending work_resched: bl schedule @@ -642,6 +641,7 @@ ret_to_user: ldr x1, [tsk, #TI_FLAGS] and x2, x1, #_TIF_WORK_MASK cbnz x2, work_pending +no_user_work_pending: enable_step_tsk x1, x2 no_work_pending: kernel_exit 0 diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index e18c48cb6db1..fde59c1139a9 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -399,18 +399,30 @@ static void do_signal(struct pt_regs *regs) restore_saved_sigmask(); } -asmlinkage void do_notify_resume(struct pt_regs *regs, - unsigned int thread_flags) +asmlinkage void prepare_exit_to_usermode(struct pt_regs *regs, + unsigned int thread_flags) { - if (thread_flags & _TIF_SIGPENDING) - do_signal(regs); + do { + local_irq_enable(); - if (thread_flags & _TIF_NOTIFY_RESUME) { - clear_thread_flag(TIF_NOTIFY_RESUME); - tracehook_notify_resume(regs); - } + if (thread_flags & _TIF_NEED_RESCHED) + schedule(); + + if (thread_flags & _TIF_SIGPENDING) + do_signal(regs); + + if (thread_flags & _TIF_NOTIFY_RESUME) { + clear_thread_flag(TIF_NOTIFY_RESUME); + tracehook_notify_resume(regs); + } + + if (thread_flags & _TIF_FOREIGN_FPSTATE) + fpsimd_restore_current_state(); + + local_irq_disable(); - if (thread_flags & _TIF_FOREIGN_FPSTATE) - fpsimd_restore_current_state(); + thread_flags = READ_ONCE(current_thread_info()->flags) & + _TIF_WORK_MASK; + } while (thread_flags); } -- 2.1.2 From mboxrd@z Thu Jan 1 00:00:00 1970 From: cmetcalf@ezchip.com (Chris Metcalf) Date: Tue, 20 Oct 2015 16:36:08 -0400 Subject: [PATCH v8 10/14] arch/arm64: adopt prepare_exit_to_usermode() model from x86 In-Reply-To: <1445373372-6567-1-git-send-email-cmetcalf@ezchip.com> References: <1445373372-6567-1-git-send-email-cmetcalf@ezchip.com> Message-ID: <1445373372-6567-11-git-send-email-cmetcalf@ezchip.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org This change is a prerequisite change for TASK_ISOLATION but also stands on its own for readability and maintainability. The existing arm64 do_notify_resume() is called in a loop from assembly on the slow path; this change moves the loop into C code as well. For the x86 version see commit c5c46f59e4e7 ("x86/entry: Add new, comprehensible entry and exit handlers written in C"). Signed-off-by: Chris Metcalf --- arch/arm64/kernel/entry.S | 6 +++--- arch/arm64/kernel/signal.c | 32 ++++++++++++++++++++++---------- 2 files changed, 25 insertions(+), 13 deletions(-) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 4306c937b1ff..6fcbf8ea307b 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -628,9 +628,8 @@ work_pending: mov x0, sp // 'regs' tst x2, #PSR_MODE_MASK // user mode regs? b.ne no_work_pending // returning to kernel - enable_irq // enable interrupts for do_notify_resume() - bl do_notify_resume - b ret_to_user + bl prepare_exit_to_usermode + b no_user_work_pending work_resched: bl schedule @@ -642,6 +641,7 @@ ret_to_user: ldr x1, [tsk, #TI_FLAGS] and x2, x1, #_TIF_WORK_MASK cbnz x2, work_pending +no_user_work_pending: enable_step_tsk x1, x2 no_work_pending: kernel_exit 0 diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index e18c48cb6db1..fde59c1139a9 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -399,18 +399,30 @@ static void do_signal(struct pt_regs *regs) restore_saved_sigmask(); } -asmlinkage void do_notify_resume(struct pt_regs *regs, - unsigned int thread_flags) +asmlinkage void prepare_exit_to_usermode(struct pt_regs *regs, + unsigned int thread_flags) { - if (thread_flags & _TIF_SIGPENDING) - do_signal(regs); + do { + local_irq_enable(); - if (thread_flags & _TIF_NOTIFY_RESUME) { - clear_thread_flag(TIF_NOTIFY_RESUME); - tracehook_notify_resume(regs); - } + if (thread_flags & _TIF_NEED_RESCHED) + schedule(); + + if (thread_flags & _TIF_SIGPENDING) + do_signal(regs); + + if (thread_flags & _TIF_NOTIFY_RESUME) { + clear_thread_flag(TIF_NOTIFY_RESUME); + tracehook_notify_resume(regs); + } + + if (thread_flags & _TIF_FOREIGN_FPSTATE) + fpsimd_restore_current_state(); + + local_irq_disable(); - if (thread_flags & _TIF_FOREIGN_FPSTATE) - fpsimd_restore_current_state(); + thread_flags = READ_ONCE(current_thread_info()->flags) & + _TIF_WORK_MASK; + } while (thread_flags); } -- 2.1.2